Turns out I did manage to become one of the finalists for the Google Da Vinci Code Quest. DG and I received the prop cryptex yesterday. The password for the cryptex is printed right on the packaging—”GRAIL”—but DG was highly amused to discover that the prop was so simple, you only need to line up the last two letters to open the thing.
There’s one more part to the game—a timed trial of five puzzles. I imagine whoever wins will either be a games genius or have enlisted the help of her various puzzle-expert friends, but DG and I plan to give it a go anyway.